/*
 * Copyright 2009 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.gwt.gdata.client.impl;

import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.core.client.JsArray;
import com.google.gwt.core.client.JsArrayBoolean;
import com.google.gwt.core.client.JsArrayInteger;
import com.google.gwt.core.client.JsArrayNumber;
import com.google.gwt.core.client.JsArrayString;

/**
 * Code adapted from
 * http://code.google.com/p/gwt-in-the-air/source/browse/trunk/src/net/ltgt/gwt/jscollections/client/JsArrays.java.
 * 
 * Provides utility methods for interacting with Arrays in GWT.
 */
public final class ArrayHelper {
  public static JsArrayString fromArray(String... values) {
    if (GWT.isScript()) {
      return reinterpretCast(values);
    } else {
      JsArrayString ret = JavaScriptObject.createArray().cast();
      for (int i = 0, l = values.length; i < l; i++) {
        ret.set(i, values[i]);
      }
      return ret;
    }
  }
  public static JsArrayBoolean fromArray(boolean... values) {
    if (GWT.isScript()) {
      return reinterpretCast(values);
    } else {
      JsArrayBoolean ret = JavaScriptObject.createArray().cast();
      for (int i = 0, l = values.length; i < l; i++) {
        ret.set(i, values[i]);
      }
      return ret;
    }
  }
  public static JsArrayInteger fromArray(int... values) {
    if (GWT.isScript()) {
      return reinterpretCast(values);
    } else {
      JsArrayInteger ret = JavaScriptObject.createArray().cast();
      for (int i = 0, l = values.length; i < l; i++) {
        ret.set(i, values[i]);
      }
      return ret;
    }
  }
  public static JsArrayNumber fromArray(double... values) {
    if (GWT.isScript()) {
      return reinterpretCast(values);
    } else {
      JsArrayNumber ret = JavaScriptObject.createArray().cast();
      for (int i = 0, l = values.length; i < l; i++) {
        ret.set(i, values[i]);
      }
      return ret;
    }
  }
  public static <T extends JavaScriptObject> JsArray<T> fromArray(T... values) {
    if (GWT.isScript()) {
      return reinterpretCast(values);
    } else {
      JsArray<T> ret = JavaScriptObject.createArray().cast();
      for (int i = 0, l = values.length; i < l; i++) {
        ret.set(i, values[i]);
      }
      return ret;
    }
  }
  public static String[] toArray(JsArrayString values) {
    if (GWT.isScript()) {
      return reinterpretCast(values);
    } else {
      int length = values.length();
      String[] ret = new String[length];
      for (int i = 0, l = length; i < l; i++) {
        ret[i] = values.get(i);
      }
      return ret;
    }
  }
  public static boolean[] toArray(JsArrayBoolean values) {
    if (GWT.isScript()) {
      return reinterpretCast(values);
    } else {
      int length = values.length();
      boolean[] ret = new boolean[length];
      for (int i = 0, l = length; i < l; i++) {
        ret[i] = values.get(i);
      }
      return ret;
    }
  }
  public static int[] toArray(JsArrayInteger values) {
    if (GWT.isScript()) {
      return reinterpretCast(values);
    } else {
      int length = values.length();
      int[] ret = new int[length];
      for (int i = 0, l = length; i < l; i++) {
        ret[i] = values.get(i);
      }
      return ret;
    }
  }
  public static double[] toArray(JsArrayNumber values) {
    if (GWT.isScript()) {
      return reinterpretCast(values);
    } else {
      int length = values.length();
      double[] ret = new double[length];
      for (int i = 0, l = length; i < l; i++) {
        ret[i] = values.get(i);
      }
      return ret;
    }
  }
  public static <T extends JavaScriptObject> T[] toArray(JsArray<? extends T> values) {
    if (GWT.isScript()) {
      return reinterpretCast(values);
    } else {
      int length = values.length();
      @SuppressWarnings("unchecked")
      T[] ret = (T[]) new JavaScriptObject[length];
      for (int i = 0, l = length; i < l; i++) {
        ret[i] = values.get(i);
      }
      return ret;
    }
  }
  private static native JsArrayString reinterpretCast(String[] value) /*-{ return value; }-*/;
  private static native String[] reinterpretCast(JsArrayString value) /*-{ return value; }-*/;
  private static native JsArrayBoolean reinterpretCast(boolean[] value) /*-{ return value; }-*/;
  private static native boolean[] reinterpretCast(JsArrayBoolean value) /*-{ return value; }-*/;
  private static native JsArrayInteger reinterpretCast(int[] value) /*-{ return value; }-*/;
  private static native int[] reinterpretCast(JsArrayInteger value) /*-{ return value; }-*/;
  private static native JsArrayNumber reinterpretCast(double[] value) /*-{ return value; }-*/;
  private static native double[] reinterpretCast(JsArrayNumber value) /*-{ return value; }-*/;
  private static native <T extends JavaScriptObject> JsArray<T> reinterpretCast(T[] value) /*-{ return value; }-*/;
  private static native <T extends JavaScriptObject> T[] reinterpretCast(JsArray<T> value) /*-{ return value; }-*/; 

  private ArrayHelper() { }
  
}